While working in the commercial fertilizer industry, self-described "Manitoba farm boy" Wade Barnes saw an incredible amount of waste as farmers frequently applied too much fertilizer to their fields.

But after a trip to nearby Fargo, N.D., he was wowed by the use of satellite imagery to identify high nitrogen areas for growing sugar beets and wanted to do something similar for his customers.

Back at the fertilizer plant where he worked, he started to build a program. The farmers loved it, but as it reduced the amount of fertilizer the company's best customers were buying, it wasn't good for the fertilizer business.

So "pushed by the farmers" to start his own business, Mr. Barnes co-founded Farmers Edge Precision Consulting Inc. in 2005. The Winnipeg-based company specializes in precision agriculture - including variable rate technology (VRT) that uses satellite imagery to pinpoint when and where to plant and how much to fertilize - to help growers increase crop production and become more sustainable. The company has operations in Canada, the United States, Eastern Europe and South America.

"Once I saw the differences in the areas of the field, the variability, it opened my eyes," Mr. Barnes says. "I realized how uninformed we were because we didn't have any information to make decisions. We were just winging it and these farmers were spending millions of dollars on fertilizer. The technology allows farmers to optimize their fertilizers. The whole business of farming has changed."

Fertilizer is a huge issue for farmers and the environment. Since the use of commercial fertilizer correlates directly to increased yield (generally estimated at between 30 to 50 per cent), farmers want to use enough to ensure a good crop.

But if too much fertilizer is used - particularly nitrogen fertilizer and other crop inputs such as pesticides and herbicides - the runoff can go into the groundwater, polluting water supplies and damaging natural habitat. The increased use of nitrogen fertilizer has also resulted in the formation of atmospheric nitrous oxide (N2O), a potent greenhouse gas contributing to stratospheric ozone depletion and global warming.

But changes in how fertilizer is used - when fields are fertilized and how much is used - can reduce N2O emissions, according to research at the University of California, Berkeley.

"When the harvest is done, the goal should be that very little fertilizer is left in the ground," Mr. Barnes says. "The technology essentially allows farmers to be green but, at the end of the day, to be green with a purpose and make a lot more money by doing it."

Recently, Farmers Edge has begun to focus on water, using satellite imagery and real-time information to determine the right amount of irrigation. With droughts occurring in many parts of the world, water is a valuable commodity.

Hortau Inc. has also developed high-tech solutions to irrigation, but with an approach centred on the plants. The company, based in St. Romuald, Que., with offices in California and Colorado, offers wireless, Web-based irrigation management systems to about 1,000 growers throughout North America. Their solar-powered technology reports back to the farmer how plants are doing in real time, before plant stresses such as drought can negatively affect the crop.

Agriculture accounts for about 70 per cent of water used in the world today. Jocelyn Boudreau, an agricultural engineer who co-founded Hortau in 2002, estimates its technology can save roughly 25 to 30 per cent of that water, as well as the same amount of energy used for pumping the water for irrigation.

"Most farmers tend to overwater to be on the safe side," Mr. Boudreau says. "You can hurt the yield just as much by overwatering as underwatering and the excess water can push the fertilizers down to where the crop can't use them. "

That's a huge advantage for the environment, as well as for the farmers. While the cost to use Hortau's technology can be anywhere from $10 to $100 an acre each year, Mr. Boudreau says it's cost effective with the payback usually covered by the first crop. In some areas where there's restricted water, such as Colorado and Nebraska, or drought-stricken California, Mr. Boudreau says their technology is seen as critical. "Depending on the growth stage of the crop, the season, the weather conditions - it's a tricky assessment. You can't do that just by eyeing it. A precision tool comes in very handy."